1. Field of the Invention
The present invention relates to an attachment structure for a pick-up device used in an electrical stringed musical instrument such as an electric guitar, etc.
2. Prior Art
FIG. 5 shows a cross-section of the attachment structure of a pick-up device used in a conventional acoustic or semi-acoustic electric guitar.
In FIG. 5, the reference numeral 1A is a front board or sounding board which forms the front surface of a hollow resonating body 1 of a guitar. A lower bridge 3 is fastened to the outer surface of the front board 1A so that the strings 2 are installed in the perpendicular direction thereof. In addition, piezo-type pick-ups 4A and 4B for picking up the sound of low-notes (of the low-note strings) and high-notes (of the high-note strings) respectively are fastened to the inner surface of the front board 1A with a lower bridge reinforcing plate 5 in between. The pick-ups 4A and 4B are installed at a location positionally corresponding to the lower bridge 3.
Each one of the piezo-type pick-ups 4A and 4B is covered with a covering 6 that is made of an ABS resin, etc., and the covering 6 is fastened to the lower bridge reinforcing plate 5 by putty 7. Putty 7 is used because a high-viscosity putty is effective in allowing the piezo-type pick-ups 4A and 4B to pick up the vibrations of the front board directly.
The reference numeral 8 in FIG. 5 is a string-carrying member or string carrier that is called a "saddle", and the string-carrying member 8 supports a plurality of strings 2 on its upper surface. This string-carrying member 8 is installed, together with a pick-up device 10 which converts the vibrations of the strings 2 into electrical signals, in an accommodating section 9 which is a recess formed in the center of the upper surface the lower bridge 3. The pick-up device 10 includes a long, slender piezo-electric element that faces the respective strings 2 and is formed in a band-shape so that it can face all the strings 2. In addition, the pick-up device 10 is connected to an electric circuit (not shown) via a cable 11.
As seen from the above, the pick-up device 10 and string-carrying member 8 of the conventional guitar are accommodated inside the accommodating section 9 formed in the lower bridge 3 and pressed by the strings 2.
However, the lower bridge 3 is ordinarily made of wood, and it is difficult to form the inside bottom surface of the accommodating section 9 of the lower bridge (against which the pick-up device 10 is tightly pressed) with a high degree of flatness. In cases where the flatness degree is low, it is difficult to pick up clean harmonious sounds; on the other hand, finishing the inside bottom surface to a high degree of flatness requires considerable skill and effort.
Furthermore, the height of the strings 2 may change due to deformation of the front board and neck (not shown) of the guitar, and this causes problems in terms of tone color, sound volume, playing characteristics, etc. The only way to solve such a problem in the prior art instrument is to adjust the height of the strings 2 by planing the string-carrying member 8. However, the planing of the string-carrying member 8 also requires a high degree of skill; and if such an adjustment is necessary just before playing in a concert, etc., there is no way to make such an immediate adjustment. Furthermore, since the piezo-type pick-ups 4A and 4B are fastened to the front board 1A by putty 7, vibration in the front board 1A may cause the putty 7 to peel off; and in addition, since the piezo-type pick-ups directly pick up vibrations of the front board, the sound would vary depending upon the type and manner of attachment of these pick-ups by the putty, and uniform quality sound cannot be obtained.